This invention relates to a lubricating collar for applying lubricant to the outer surface of a cable preparatory to pulling the cable into a conduit. More particularly, the present invention relates to such a collar having lubricant discharge orifices at a lubricating station which is openly exposed to the cable entry end of the collar and immediately followed by a brush having elongated fibrous bristles projecting radially into the internal passageway of the collar to spread lubricant on the outer surface of the cable.
In the placement of underground cables, particularly telephone communication cable and electric utility cable, procedures are necessary to protect the cable from damage during the placement operation. A flexible feeder tube having a weakened longitudinal area in the side wall thereof is now available for protection and guidance of a cable while fed from a supply reel to an underground circuit. The feeder tube can be stripped from the cable laterally by severing the tube along a weakened side wall section to meet the need for placing cable having connectors attached to the conductors which are part of the cable during the placement operation. A lubricating collar is attached to the end of the feeder tube to apply lubricant onto the surface of the cable before entry into the feeder tube. The collar is split longitudinally and provided with fastening means for releasably joining together the halves of the split collar. The fasteners are used to release the individual halves of the collar for lateral removal from their normally-surrounding relation with the cable. The collar is made up of a funnel-shaped entry section; a downstream lubricating section; and a succeeding tubular end part dimensioned to fit within the flexible feeder tube. Rubber discs with radial slots extend from a central opening to form wipers for distributing luricant on the cable. One wiper is positioned between the funnel-shaped entry section and the lubricating section and another wiper is positioned between the lubricating section and the tubular end part. The various parts of the collar are held together by bolts in tension extending along the outer side wall of the collar. Another form of lubricating collar is shown in U.S. Pat. No. 4,028,473. The collar in this patent is not split and includes three disc-shaped wipers arranged at spaced-apart locations within the collar which is also an assembly of parts held together by bolts in tension. One wiper encloses the entry side of a lubricating section and two spaced-apart wipers are situated at the discharge side of the lubricating section.
U.S. Pat. Nos. 4,046,225 and 4,063,617 disclose flexible discs in a lubricating collar assembly at opposite sides of a lubricant-filled chamber. The flexible rubber discs shown in these patents are used to seal the lubricant chamber area to the cable and spread the lubricant about the surface of the cable upon withdrawal from the lubricant-filled chamber.
I have discovered that the flexible rubber discs at the entry side of the lubricant-filled chamber, such as disclosed in the aforesaid patents and application, are detrimental to controlling the discharge of lubricant into the collar. Moreover, use of such a disc in the past required a collar construction made up of a number of parts that must be bolted together in a liquid-tight manner to avoid a loss of lubricant from the collar. The cable invariably moves from its desired central location in the aperture of the wiper. This strips more lubricant from one side of the cable than the diametrically-opposite side of the cable but more importantly, may damage the wiper. The flexibility of the wipers and, hence, also their required sealing relation in the collar assembly, are subject to the environmental temperature as well as deterioration, including attack by solvents or other chemicals that contact the wipers at one time or another. These disadvantages as well as others are overcome by the lubricating collar of the present invention.